Steps to create COMAddIn using NetOffice

Jun 10, 2014 at 3:16 PM
Edited Jun 10, 2014 at 8:44 PM
How to add winform user control on spreadsheet using NetOffice? I could not find sample or documentation for this.
I am able to do using VSTO.
e.g. for adding WinForm Button control, VSTO adds Microsoft.Office.Tools.Excel.Controls.Button rather than System.Windows.Forms.Button